Belt-tensioning apparatus



Feb. 28, 1928.

A. E. NIELSEN ET AL BELT TENSIONING APARATUs Filed AugE 13, 1924 2Sheets-Sheet 1 Feb. 2s, 1928.

1,660,520 A. E. NIELSEN ET AL BELT TENsoNING APPARATUS Filed Auz.15,1924 2 Sheets-Sheet 2 Patented' Feb. 28,L 1928.`

UNITED Smits AAixam QFFICE@ AN'roN E. NIELSEN AND GEORGE ol NiiiiisiimorNEW YORK, N. yY.`

BELT-TENSIONING vAieiefi'nn'iris.

Application filedAugust 13, 1,924. userialilNo. 731,719.

This invention relates to certain new and useful improvements in belttensioning apparatus and especially to such as are readilyv adjustablet0 meet the'vefyllls @OndltlODS 0f service. many industries, power istransmitted by means of belts of various kinds,

which connect the'source of power with the machine tobe driven, and theeconomical transmission of power is, in many cases, a serious problem.'For instance, ay `single inotorinay be designed to operate con/sider-Akable number of individual machines, andat justed according to the load.vThat'is,ito

drive six ojr eight machines, the belt should be considerably tighterthan when but one or two operate. Upon the other hand, inv

order to prevent the belt from sli iindue' wear thereon, the belt sho dbe no tighter than is necessary to drive satisfactorily under any givenload, as excessive tension stretches and rapidly deteriorates' thebelt." In many instances, load changes occur at frequent intervals and,unless' the belt tension is altered to meet these conditions,uneconomical resultsY occur, and it is an important object of myinvention to prodi'ice a Vbelt tensioning device which will not onlymaintain the proper tension of the belt at. alltimes, but one in whichthe tension canl be adju'sted quickly and with a minimum of trouble. 'f

v In addition, itis an object of my invention to produce a device whichis adaptable to existing power transmission systems of all kinds, andone whichv can be applied thereto lin 'almost any location with aminimum of troubleandexpense.

In the drawings formingpartof this application, we have illustrated twoembodiments of` our invention, .but itwillbe under,- stood thatthese areset forth for illustrative purposes only, as the invention` may-beembodied in many other forms'and structures.

' Referring now tothe drawings,-

Fig. l is aside elevationjofmy improvec belty tensioning `deviceassociated with or applied to' a power unit, i l

ping and` u.

Fig. 2 is a sectional view ofthe tensioning device taken on the lines2-'2'of Fig'. l, looking in thedirection ofthe arrows. v

Fig. 3 is'an enlarged detailed view of the mechanism for adjusting thetension. l

Eig. 4: is a sidev elevation of, another form of my invention adaptedfor use with i power plants generally. f ,i i V Y l y ig. -5 isasectional view of thesame taken onlines 5-5 of-Fig. 4L, looking in thedirection the arrows. f .o f

A(Slis a horizontal sectionofthis form of apparatus taken on lines V6 6ofFig. 5 and looking downward thereon. f Y

Similai'numeials of reference indicate like parts in all the figures.- Ai' i in the structure shown in Figs. l, 2 and 3 ofthe drawings, 1rindicates a suitable base or support, upon whichis mounted a power y hasa drive shaftS which,by means of gears (not shown), is connected to'andoperates the transmissionor'power shaft 4. This shaft is adapted torotate in a suitablebearling 5 mounted in a cylindrical housing 6extending from the face 7 of the, gear case. The shaft carries a `poweror driving pul- 1ey8 A tensionv member, comprising an arm 9 and a'cylindrical sleeve 10, thejlatter of which is'mounted upon the bearing6 to roo tate freely thereon, is also provided, and the outer end of thearm is' provided with a slot, in which is adjustably secured the end 1lof the shaft l2 which carries the tension pulley 13', a'niit le servingto secure the shaft 12 in the desired position'. Another tension member,'consistingof an arm land asleevefl6,y is also provided,` the lattersleeve being mounted to rotate freely upon the outside of the sleevel0.` A segmentof the periphery of this sleeve f1 (4), is-providedwith aseries of teeth 17, and the arm 15 carries a pin or stud. 18, upon whichisvmount'edk a pawll9 the studby any suitable means Sush'as, acot- .ter'pin 2l, and is adapted lto engagel and cohaving va coiinterlbalaned orvweighted end,` z '20'. MThis pawl yis removably secured upon operatewith' the tjeethfl'?Y on the sleeve 10,

above described.

' To thebase l is also secured, by' any siiit-y able means, such as astud 22, one end o fv a tensioning `spring 23;V .The other end jof theill ` stud or shaft 27, having a reduced or teeth 17, tending` to rotatethe sleeve 10 in sprin,` is connected by any suitable means,

such as a stud 24, with the outer end of the arm 15. i i

The structure illustrated in F igs. t, 5 and 6 of the drawings embodiesa similar device adjustably mounted upon an independent frame orstandard which can thus beni-ade to cooperate with belt transmissionsystems already instilled. ln this construction, 1 indientes the basewhich carries-the `upright 25 provided with an extended slot 26, andtheseparts are j neiierablyloi'nied ot an integral casting.` Thetensionir'ig members, similar to those above described, are mounted toindependently rotate upon an enlarged attened portion 28 and a threadedextension 29. The flattenedV portion Q8 is ot' such size and shape as tohave a slidable lit in the slot 26, and the stud is adjustably securedto the frame 25 by means of the nut 30. In asimilar manner, aspring-supperting plate 31, having at the center and ends thereot studs32, 33 and 34 and Vtongue portions or flanges 85 is mounted upon a bolt36, liavinc`g-r a nut 37. Then assembled, as shown in Fig. 4l, the bolt36 passes through the slot, and the tongues 35` engagewith the sidesthereof, a

retaining plate 39 and nut 87 clanipingthe parts in thedesired position.i

Reterring now to the structure shown in `Figs.` 1, 2 and 3,`theoperation will be readily understood; The parts being` disposed asy inFig- 1,-the belt passes around the power pulley 8 and also contactswiththe tension pulley 12. Proper tension is maintained upon the belt byreason of the fact thatV puh ley 12 is being" constantly forced tothelett in the direction of the upper. arrow, the spring 28 tending tocontract, pulls the lower end ofthe arm 15 to the right, and the pawl 19being seated between two of the that direction. Should the 'tensionotthe device be too great. it can be instantly reduced by simply slipping`the pawl out ot engage" ment with the teeth` 1T and permit-ting it toengage the teeth Jfurther to the right see Fig. 1). Should the tensionbe too little, it can be increased to any desired extent by causingthepulley to` engage teeth 17 to the Vlett ot those shown in Fig. 1.

The operation ot the structure shown in Fig. i is substantially thesaine. The tension may be increasedor decreased, according to theparticular teeth with which the` pulley is causedto engage, and thedevice is susceptible of practically `universal application,` 4as thetension device can be Vmade to operate'in either direction. `Forinstance,

vas shown in full line in Fig. 4l, parts are engaged to cause a tensionupon the belt in the direction shown by the upper arrowviii Fig. 1. It',however, it is desired `to `adapt the device for use in an oppositedirection all.

that is necessary is to remove the Cotter pin 21 from the stud 18,reverse the position of the pawl, and move the tension pulley to apeproXii'nately thev position shown in dotted i line in Fig. 4. Uien thisis done, the outer @end of the spring 23 is disengaged troni tbe stud 84and connected to stud 32, in which position the parts will operateexactly the saine except in an opposite direction.

Vlily means of this adjustability, the tensioning` device can beapplied, to any existingr system;` The base may be secured upside down,as against the ceiling', upright upon one which can be regulated to meetthe vaf rying conditions of service and yet one whicliis rugged,substantial, composed ot fevvlparts, and which is therefore not likelyto get out `of order. i y

While we have sli-own our invention as applied to a belt of leather,canvas, rubber or the lilre,"its application is by no means necessarilyso limited. By the use ot prop`-` erly'shapcd tensiony pulleys otherformsv of belts, such as link or chain belts may-,be

accommodated, in fact, any form of power transmission contrivances whichrequire*` .pr-opertensioning can` be controlled.

Although we have shown two forms ot ourinvention which are typicalen'il'iodinients o'foui' fundamental idea, `these are by no means theVonly terms. Various modifications and changes may be inadein struct-urei troni those above described and illustrated, without departing fromthe spirit otlthis invention. y

That we claim and desire Letters Patent is;

1. A belt tensioning' apparatus comprising a pair of concei'itricallypivoted movable arms, a belt vengaging Vroller pivoted atV the out-ervend of one ot said arms, a spring operatively engaging the outer end otthe other of said arms, and a ratcliet-andpawl connectionbetweenintermediate portions ofsaid arms. i

to "secure by 2." 1n a belt' tensioning apparatus, tbeconrA posedaboutthe pivotal center of said arm,

a spring operatively connected. to the outer end ofthe other of saidarms and to a` suitable Fsupport, and a movable `pavvlpivoted to anintermediate portion of the `last-men- Vtioned arm and adapted' toengage withtlie teeth of the firstmentioned arni. i

3. VIn a belt tensioning apparatus the-coni bination of a pair ofconeentrieally pivotedv arms, a belt engaging roller adjustably mountednear the end of one of said arms, tension controlling means operativelyconnected to the other of said arms, and an adjustable connectionbetween said arms comprising a rack and a reversible pawl.

4. A belt tensioning apparatus comprising a belt-carrying spindle, ahousing` therefor, a movable arm having a tension roller pivoted'nearthe outer end thereof and having a sleeve for eo-opeifating with thehousl0 ing, a second arm movably mounted upon said sleeve, a spring(1o-operating with the the sleeve of the first-mentioned arm.

' ANTON E. NELSEN-.

GEORGE o. NIELSEN.

